The present invention relates to a rotating laser beam irradiating apparatus, and more particularly to a rotating laser beam irradiating apparatus which, by synchronizing an emission timing of a pulse laser with a rotation of an irradiating means, makes it possible to describe intermittent dot-shaped marks, to tremendously increase a visual recognition distance, and to enlarge a work area.
Widespread up to now in a work area such as a construction site has been a constructing process of rotating a laser light beam to form a rotating laser beam plane, and of then performing the construction using the reference plane thus produced A red-colored laser diode, reflecting recent technological advances in a semiconductor laser, is employed in the rotating laser beam irradiating apparatus for forming the rotating laser beam plane. The rotating laser beam irradiating apparatus using the red-colored laser diode is battery-operable and easy to handle, thus being widely used in a construction work area.
For example, a prior art rotating laser beam irradiating apparatus comprises a laser light projector and a laser light irradiating unit which rotates around an optical axis of the laser light projector so as to irradiate with a laser light deflected by 90 degrees to the optical axis of the laser light projector. The prior art rotating laser beam irradiating apparatus, by rotating the laser light irradiating unit, makes it possible to form the reference plane or to provide a reference line on an object such as a wall surface.
However, the prior art rotating laser beam irradiating apparatus using the red-colored laser diode had a limit in an output of the semiconductor laser, and in addition had a restriction to an irradiating output of the laser in order to assure safety for the eyes of a worker. This resulted in a problem that, in a comparatively bright work area and at a position a little away from the rotating laser beam irradiating apparatus, it becomes impossible to visually recognize the rotating laser beam plane.
It can be considered, in order to overcome the restriction to the laser irradiating output, to employ a green laser to which a spectral luminous efficiency of the human eye is high.
However, even if the green laser is employed instead of the red laser, the following problem emerged especially when increasing the laser irradiating output: The laser beam emitted was-too bright for the eyes of a worker, which made it impossible to assure the safety, to realize a tremendous increase in the visual recognition distance, and to enlarge the work area.
Moreover, employed as a means for generating the green laser can be a solid-state laser generating apparatus using a secondary higher harmonics generator being widespread in recent years. The solid-state laser generating apparatus is able to generate a comparatively high output of green laser, but the power consumption thereof was great and the generating apparatus was found to be difficult to drive continuously for a long time by the battery-operation.